1. Field of the Invention
The present invention relates generally to the field of cleansing the interior surfaces of enclosures, more particularly to cleansing the interior surfaces of substantially vertical longitudinal enclosures, and specifically to degreasing the interior surfaces of kitchen exhaust ducts of the type most commonly fed by intake hoods most commonly disposed above stoves.
2. General Background
The use of oils in cooking commonly results in air borne grease and smoke which is commonly vented out of restaurant kitchens with an intake hood and exhaust duct through which the grease and smoke laden air is induced by means of a fan and expelled outside to the ambient atmosphere exterior to the building in which the kitchen is located. This practice is important for sanitary and safety considerations among other factors such as the reduction of offensive odors. If airborne grease is not vented out of the kitchen it will readily result in a conflagration which will readily destroy the kitchen if not the entire building in which the kitchen is located.
The airborne grease, however, in being vented out of the kitchen through a duct, commonly accumulates upon the interior surfaces of the duct walls and creates a fire hazard there, particularly if the duct is connected to an intake hood above a stove which is perhaps the most common arrangement known. In recognition of this fire hazard it is a commonplace in the United States to require periodic degreasing of the interior surfaces of these ducts as a matter of fire code regulation. Restaurants commonly known as fast food franchises are particularly subject to rather frequent degreasing of their kitchen exhaust ducts because of the large volume of airborne grease carried therethrough over time and the high rate of grease accumulation resulting therefrom. Quarterly, monthly, fortnightly and even more frequent periodic degreasings are commonly mandated by state regulations for the interior surfaces of the ducting in many restaurant kitchen ventilation exhaust systems in order to avoid the dangerous fire hazard which would otherwise result.
The current method of degreasing restaurant kitchen exhaust ducts is highly labor intensive. It involves the transport of high pressure nozzles upon hoses several stories high in many instances, opening lateral hatches to the ducts at various elevations, and hand directing the highly pressurized and heated jet of water and steam from the nozzle against the interior walls of the duct. The work is extremely uncomfortable for many reasons including heat, elevated humidity, cramped quarters, and weighty apparatus. Visibility inside the duct is minimal and communication between team members impeded by the structure necessarily interposed between the person wielding a nozzle and the person controlling the pump. The present inventor is thoroughly knowledgeable of this work and has and has had many employees who will readily attest to the arduousness of this work.
The water used in this operation is commonly collected with plastic sheeting disposed beneath the bottom end of the duct, typically disposed under an intake hood and above a stove, and directed into buckets disposed upon the floor of the kitchen and subsequently poured down a drain. The expense involved with this operation is considerable because of the difficulty of the labor involved, because of the expense of the equipment required, and because of the fact both must be transported on site periodically. And the effectiveness of this operation, being wholly dependent upon the people directing the pressurized jets of heated water and steam in conditions of minimal visibility, is open to question. It is effective if properly executed but there is no known manner of ascertaining the level of cleansing achieved nor of confirming that the operation was properly executed.